Filling in section view

I'm designing a component that's to be fitted in a concrete structure. To illustrate what this will look like, I mock up the concrete structure in a part studio and fit my steel part and concrete in an assembly. Then I create a drawing of the assembly with a section view. The problem now is that the concrete part has the diagonal lining and not the traditional "concrete look".Even if I designated the material in the part studio to be concrete.

Any suggestions? Or do I really have to dig up my long since forgotten CD with AutoCad LT 2012?

Well, I don't think thats clever... I really think thats awfull and We should't do that

I believe that Onshape are doing a great job in the modeling area (Part Studios and Assemblies) but Drawings are very, very loose compared to traditional CAD. So, please in the next releases try to put the focus on Drawings

Cheer up guys you know what they saySome things in life are bad They can really make you madOther things just make you swear and curseWhen you're chewing on life's gristleDon't grumble, give a whistleAnd wait for the next release in 3 weeks...